Device for cutting sheet material



United States Patent Appl. No. Filed DEVICE FOR CUTTING SHEET MATERIAL 4Claims, 12 Drawing Figs.

hit. (I 826d 1/04 Field otSearch 83/527,

Primary Examiner-James M. Meister Attomey-Mc Cormick, Paulding and HuberABSTRACT: A cutter head for use with an automatically controlled sheetmaterial cutter utilizes a reciprocating tool having a cutting edgefacing the work and located in a plane perpendicular to the axis ofreciprocation. The tool and its chuck are rotatable about the axis ofreciprocation to allow the cutting edge to be maintained tangent to theline of cut. A presser member engages the work to limit the downwardmovement of the cutter head and is adjustable relative tothe main frameof the head to adjust the maximum amount by' which the tool projectsbeyond the work engaging face of the presser member during itsreciprocation.

PATENTEDDEE22|97B 354M539 SHEET 1 OF 5 CUTTER cowomow INPUT COMPUTER 4OTOOL ANGLE I l 48 54 I X MOTION j 46 50 Y MOTION i j .T

HHECIE INVENTORS HEINZ JOSEPH GERBER,

ROBERT .1. PAVONE ATTORNEY PATEN'IED 052221970 SHEET 2 [IF 5 pmmm3,648,699

SHEET 3 [IF 5 PATENTEUBEB22|97B 345436 SHEET 5 OF 5 [FEEDER '1 DEVICEFOR cu'rrINc SHEET MATERIAL RELATED APPLICATION This application is adivision, of copending patent applica tion Ser. No. 581,065, filed Sept.21, 19.66 and entitled Device For Cutting Sheet Material, now U.S. Pat.No. 3,477,322.

BACKGROUND or THE INVENTION SUMMARY. OF THE lNVENTION The inventionresides'in a cutter head of a type adapted for attachment to anumerically controlled automatic positioning device or the like forcutting a piece of sheet material located on an associated supportingsurface over which the cutter head is movable. Cutting of the workpieceis accomplished by a reciprocating tool having a cutting edge on itslower end. The tool is supported for reciprocation and rotation aboutits longitudinal axis relative to a main frame and is reciprocated by achuck in turn driven by a reciprocating drive means to which it isconnected for rotation about the'axis of reciprocation. A presser memberonthe frame has a surface generally perpendicular to the axis of toolreciprocation that engages the surface of the work material to limit themovement of the cutter head toward the material. In its reciprocationthe BRIEF DESCRIPTION or THE DRAWINGS FIG. 1 is a perspective viewshowing a cutting device utilizing a cutter head embodying the presentinvention.

FIG. 2 is a schematic diagram of the control system of the FIG. 1device.

FIG. 3 is a side elevational view of the cutter head of the device ofFIG. 1.

FIG. 4 is a front elevational view of the-cutter head of the device ofFIG. 1 taken on the line 4-4 of FIG. 3.

FIG. 5 is a vertical. sectional view taken on the line 5-5 of FIG. 4.

FIG. 6 is a vertical sectional view taken on the line 6-6 of FIG. 3.

FIG. 7 is a vertical. sectional view taken on the line 7-7 of FIG. 6.

FIG. 8 is. a fragmentary horizontal sectional view taken on I the line8-8 of FIG. 4, this FIG. being drawn on an enlarged scale from that ofFIG. 4.

FIG. 9 is a .fragmentary'horizontal sectional view taken on the line 9-9of FIG. 4 and drawn on a scale still further enlarged from that of FIG.8.

FIG. 10 is a horizontal sectional view taken on the line 10-10 of FIG.6.

FIG. 11 is an enlarged 'elevational view of the cutting end of thecutting tool of the device of FIG. 1

FIG. 12 is a transverse sectional view through the cutting tool taken onthe line 12-12 ofFlG. 11..

In accordance with this invention, a cutter head is provided having areciprocating cutting tool adapted to cut a piece of sheet materiallocated generally normal to the axis of tool reciprocation. The cuttingtool may take various different forms and could, for example, be a saw'bladefor sawing the sheet material as it is reciprocated. In-this case,the tool has a definite cutting axis which is perpendicular to the faceof the material, extending across the thickness thereof, against whichthe teeth of the blade work. Preferably, however, and as shown in theillustrated embodiment, the cutting tool has a sharp cutting edge whichpierces thesheet material as the tool is reciprocated, and in this casethe cutting axis is the axis containing the cutting edge. The cutterhead is supported for movement in two dimensions over a sheet ofmaterial to be cut and means are provided for moving the cutter head sothat the axis of the tool reciprocation follows a'desired line to be cuton the sheet material. The means for so movingthe cutter head preferablyincludes a numerical controller or computer capable of accepting codedinput information and for converting such input information into commandsignals for causing the cutter head to be moved along thedesired line.In cases where the tool has a definite cutting axis, means are alsoprovided for controlling the angular position ofthe cutting toolrelative to the sheet material so that as the tool is moved along adesired line its cutting axis is maintained tangent to the line. Thecutting tool may be reciprocated at such a speed in relation to itsspeed of travel along the desired line as to produce either a continuouscut or to merely perforatethe sheet material by a series of spaced cutsor perforations.

Turning to FIG. 1, this FIG. shows a cutting device utilizing a cutterhead embodying this inventioit. In this device, the cutter head isindicated generally at 20 and a sheet of material arranged to be cut bythe cutter head is shown at 22. The support for the cutter head 20 andthe sheet of material 22 is in this case provided by an X-Y plotter ofthe type customarily used for-drawing or plotting lines or otherinformation on a sheet of paper or the like, the cutter head 20'takingthe place of the pen or printing mechanism customarily used on theplotter and the sheet of material 22 taking the place of the paper orsimilar material normally used with the plotter. The sheet of material22 may be of variousdifferent forms such as, for example, heavy paper,cardboard, plastic sheet, thin sheet metal or gasket material. In FIG.1, the broken lines 24 on the sheet 22 indicate lines along which it isdesired to have the material cut to produce desired articles. Thesearticles may,

. for example, be patterns later used for cutting other materials suchas lay-ups of cloth sheets.

The plotter shown in FIG. 1 is one which is capable of moving the cutterhead along a desired line and may take various different forms. For thepresent purposes, it is sufficient to note that the plotter includes atable 26 providing an upwardly facingsurface 28 over which the cutterhead 20 is moved. The

surface 28 supports the sheet material 22 and is preferably made fromrubber or other similar resilient'material which is sufficientlyresilient to allow the cutting edge of the cutter tool, as hereinafterdescribed in more detail, to be pressed a slight distance into thesurface 28 without cutting it. The sheet material 22 may be heldvto thesurface 28 in various different ways, but preferably the plotterincludes a vacuum hold down consisting of a plurality of tiny openings30, 30 distributed over the entire extent of the surface 28. andcommunicating with a suitable source of vacuum (not shown). The vacuumproduced on the underside of the sheet material 22 by these openingsholds the sheet material 22, and the article cut therefrom, in placerelative to the supporting surface 28. A carriage 32 is supported formovement relative to the table 26 in the direction of the X axis shownin FIG. 1 and on the carriage 32 is a part, to which the cutter head 20is attached, which is movable relative to the carriage in the Ydirection of FIG. 1. Therefore, it will be understood that by moving thecarriage 32 relative to the table and by moving the cutter head 20relative to the carriage 32 the cutter headmay be moved to any point onthe sheet material 22. The actual construction of the table 26, thecarriage 32 and the means for supporting the carriage relative to thetable may vary widely. A suitable construction of these parts is,however, shown in copending patent application Ser. No. 228,289 ofGerber and Logan, filed Oct. 4, 1962 and entitled X-Y PLO'I'TER.Reference may be had to this copending application for further detailsof the construction.

Included in the cutting device of FIG. I is a computer, or similarcontroller indicated generally at 34 for controlling the movement of thecutter head along the line to be cut, the rotation of the cutting tool,and the shifting of the cutter head between a cutting condition and anoncutting condition. The computer 34 may take any one of variousdifferent forms well known in the art and operates to generate suitablecommand signals transmitted to the cutter head and the driving'motors ofthe plotter. In the illustrated case, the computer 34 is shown to havean input device in the form of a magnetic tape transport mechanism 36which handles a magnetic tape having recorded thereon coded informationutilized by the computer to'derive the command signals. It should beunderstood, however, that this type of input has been shown for purposesof illustration and that any other type of input well known in the artcould also be used.

FIG. 2 is a schematic block diagram showing the basic control mechanismfor the FIG. 1 device. Referring to this FIG., the reference numeral 38indicates a motor associated with the cutter head 20 and operable toshift the cutter head between its cutting and noncutting condition. Inthe illustrated cutter head, as described in more detail hereinafter,this motor is a rotary solenoid which is energized to shift the cutterhead to a noncutting condition and deenergized to shift the cutter headto a cutting condition. The reference numeral 40 indicates a motor forrotating the tool about its central axis to Y change the angle of itscutting edge, or cutting axis, relative to the sheet material. In theillustrated cutter head, this motor is a stepping motor and the commandsignals transmitted thereto consist of pulses which step the motor.Associated with the motor 40 is an encoder 42 which, through the line44, supplies the computer 34 with a signal indicating the angularposition of the tool. This encoder may take various different forms, butin the illustrated cutter head it consists merely of. a switch which isoperated at one specific angular position, referred to as the zeroposition, of the tool. The computer 34, in turn, includes a register(not shown) containing a number representative of the tool angle. Eachtime the tool passes its zero position, the encoder 42 transmits asignal to the computer and the computer thereupon checks the number inthe tool angle register. If this number is not representative of thezero position,

a suitable correction is made to make it so.

The reference numerals 46 and 48 in FIG. 2 represent, respectively,motors for driving the carriage 32 in the X direction and the part ofthe carriage to which the cutter head' 20 is attached in the Ydirection. These motors may also take various different forms, butpreferably are stepping motors with the command signals supplied theretoconsisting of trains of pulses. In moving the cutter head 20 along aline not parallel to either the X or the Y axis, pulses are supplied toboth of the motors 46 and 48 simultaneously with the ratio of the pulserepetition rates of the two trains of pulses being related to the slopeof the line. Associated with the Y axis motor 46 is an encoder 50 which,through the line 52, supplies the computer 34 with information as to theactual position of the carriage 32 along the Y axis. Similarly, anencoder 54 is connected with the X axis motor 48 and supplies thecomputer 34 with information, through the line 56, as to the actualposition of the cutter head 20 along the X axis. In the preferred formof the computer 34, the input information recorded on the magnetic tapeor other record medium used by the input device 36 consists of codedinformation defining the coordinates of a number of end points betweenwhich the cutter head 20 is to be moved in sequence, the line followedby the cutter 20, therefore, usually consisting of a large number ofline increments each extending between two such points. At the start ofany one line increment the computer 34 receives information from theinput device 36 as to the coordinates of the next end point. Thesedesired .end point coordinates are then compared with the coordinates ofthe present position .of the cutter head 20, as provided by the encoders50 and 54, and the results of the comparisons are used by the computerto generate two trains of pulses transmitted respectively to the Y motor46 and X motor 48. The number of pulses supplied to the X motor aresufficient to move the carriage 32 along the table 26 a distance equalto the X component of the desired movement and the number of pulsessupplied to the Y motor 48 are sufficient to move the cutter 20 alongthe carriage 32 a distance equal to the Y component of thedesired'movement. At the beginning of the line increment, pulses arealso supplied to the tool rotating motor 40 to bring the cutting edge ofthe tool into alignment with the incremental line to be followed. Theencoders tors, the stepping motors however being the presently preferredform of drive.

The pulses transmitted to the tool rotating motor 40 may be generatedfrom information prerecorded on the record medium of the input device 36along with the end point coordinates, or the computer 34 may itselfcompute the required to'ol angle from the endpoint information and usethis computation to generate the necessary pulses for the motor 40. Theinformation for controlling the cutter condition is preferablyprerecorded on the record'medium used by the input device 36 and is usedby the computer 34 to produce proper energizing or deenergizing signalstransmittedto the motor 38. As shown in FIG. 2, the computer 34 alsopreferably has associated therewith'a unit 58 for controlling the scaleof the shape cut by the cutter head in response to a giveninput program.This unit basically operates on the output signals to the X and Y motors48 and 46 and multiplies said output signals by a selectedproportionality or scale factor. By setting the scale unit 58 to provideone scale factor the input program on the record used by the inputdevice maybe used to produce one size of end product, and by setting adifferent scale factor on the scale unit the same program may be used toproduce a different size of end product.

Turning now to FIGS. 3 to 12, these FIGS. show in more detail the actualconstruction-of the cutter head 20 of FIG. 1. Referring first to FIGS. 3and 4, the part of the plotter carriage 32 which is movable in the Ydirection of FIG. 1, and to which the cutter head 20 is attached, isindicated at 60. The cutter head itself includes a first frame fixed tothe carriage part 60 and'a second frame movable vertically relative tothe-first frame. The first frame comprises a plate 62 which is attachedto the part 60 by four screws 64,64. On either side of the plate 62, asshown in FIG. 4, are two vertical guide rails 66 and 68, respectively,attached to the plate 62 by screws 70, 70. The two vertical guide rails66 and 68 receive .therebetween a plate 72 comprising part of the secondor movable frame of the cutter head. The plate 72 is guided for verticalmovement relative'to the guide rails 66 and 68 by two linear ballbearing assemblies 74, 74 each interposed between a respective one ofthe guide rails and the plate 72. The nature of the connection betweenthe carriage part 60and the two frames of the cutter head is furtherillustrated in FIGS. 8 and 9. Referring to these FIGS., it will be notedthat the screws 70,70 which pass through the rail 68 are received inopenings in the rail' 68 which are substantially larger than the shankof the screwso as to allow the rail 68 to be moved slightly toward oraway from the opposite rail 66 to adjust the load on the bearingassemblies 74,74 and to takeup any looseness between the movable frameplate 72 and the fixed frame plate 62. Movement of the rail 68 toward oraway from the opposite rail 66 is effected by means of two eccentricheads 76,76 associated with the rail in which it is received and,depending'on the direction of its rotation, will move the rail 68 towardor away from the opposite rail 66. It will, of course, be understoodthat during such adjustment of the rail 68, theother screws 70,70 fixingthe rail 68 to the plate 62 are loosened, and that after such adjustmentis made the screws 70,70 are tightened to hold the rail in its adjustedposition. v l

The movable frame is moved relative to the fixed frameby a rotarysolenoid 38 mounted on the fixed frame plate 62, best shown in FIG. 7.The body of the solenoid 38 is located to the rear of the plate 72, or.to the left as shown in FIG. 7, and included'in the solenoid is anoperatingshaft 84 which extends forwardly through openings in the plate62 and the plate 72 and-has a lifting cam 86 fixed to its forward end.The cam 86 cooperates with a roller 88 carried by the movable frameplate 72 for rotation about 'an axis normal to-said plate. The shape ofthe cam 86 is shownin FIGS. 4 and 6. These FIGS. show the cutting headin its cutting condition, in which condition the cam 86 is out ofengagement with the roller 88 and the movable frame is held in aloweredconditionby gravity. To shift the cutter head to a noncutting condition,'themovable frame is raised from the lowered condition shown in FIGS. 4and6, this being accomplished by energizing the solenoid 38 whichrotates the cam 86 approximately 90 counterclockwise form the positionshown in FIGS. 4 and 6, causing the cam to en gage the roller 88 andlift the frame 72 to the position shown by the broken lines in'FIG. 4;In this position of the frame 72 the cutting tool is raised above thesurface of the material to be cut and is thereby prevented from engagingand cutting the material. I 1 I In addition to raising the movable frameby means of the lifting solenoid 38 and cam 86, it may also be manuallyraised and locked in an elevated position. To provide for locking in anelevated position, the movable frame 1 plate -72 as best shown in FIG,7, includes a locking plunger 89 slidably sup ported thereby and biasedrearwardly to the position shown in FIG. 7. by a helical spring 91.-Therear end of the plunger 89 normally rides in a vertical slot 93 formedin the rear plate 62. Above the groove 93, however, isan opening 95 intowhich the rear end of the plunger 89 may be placed to hold the edges98,98 each intersecting the associatedend of the cutting edge and bothlocated in a plane containing the cutting edge 94 and the central axisof the tool. The two side edges 98,98 diverge outwardly from the centralaxis in passing upwardly from the cutting edge 94 and each edge-98 isformed bytwo flat surfaces 100,100 which intersect to form the edge, the

' acute angle to each otheras'measured'through the body of the tool. Thecutting edge 94 is also fonned at a known angle to the flat 92, and inthe illustrated case, as shown in FIGS. 5 and 6, it is arrangedgenerally parallel to the flat 92.

The cutting tool 90 is supported for reciprocating movement along itscentral axis, which axis is in turn arranged generally normal to thesheet of material 22 to be cut. As shown by FIGS. 5 and 6, the cuttingtool '90 is supported for reciprocation along, and for rotation aboutits central axis by two vertically spaced bushings 102,102, which arepreferably threaded to'receive a presser member 110 having .a flatdownwardly directed face 112 adapted to engage and rest on the sheet ofmaterial to be cut during the cutting operation. The presser member 110includes a central aperture 114 through which the cutting tool 90 movesduring its reciprocation. During each cycle of tool reciprocation, thecutting edge 94 is located above the presser face 112'for a portion ofthe cycle and is located below the face 112 forthe remainder ofthe'cycle. The maximum amount by which the edge extends below thesurface 112 during a cycle determines. the thickness of material whichmay be cut, and by threading the presser member 112 in one direction orthe other relative to the guide member 104, the maximum penetration 'ofthe cutting tool stroke without moving any substantial extent into thesurface movable frame in an elevated position. The upper end of thegroove 93 is preferably curved, as shown at 9.7, so that as the movableframe is raised byhand the curved upper portion 97 of the groove earnsthe plunger 89 forwardly and out of the groove. Thereafter when theplunger is brought into registration with the opening 95 the spring 91.moves it rearwardly into the opening 95 to lock the movableframe in thecorresponding elevated position. When it-is desired to return themovable frame to its normal position, the forward end of the plunger 89may be grasped by hand and pulled forwardly to remove its rear end fromlocking relationship withthe opening Referring to FIGS. 5 and'6 thecutting 601 of the cutter head 20 is shown at 90 and consists of anelongated cylindrical element provided with a flat 92 atits upper endfor coopera tion with a chuck, hereinafter described, and shaped at itslower end to provide a sharp straight cutting edge 94. The

28 on which the sheet material is supported. Also, movement of thepresser member on the guide member 104 allows an adjustment toaccommodate tools of slightly. varying lengths-As shown in FIGS. 4 and6, a detentmeans is provided for holding the presser member in aselected angular position relative to the guide member, said detentmeans comprising a series of vertical grooves 116,116 on the outersurface of the guide member 104 and a cooperating spring .bias'ed ballplunger detent unit 118 fixed to the presser member 1 10.

The cutting tool 90 is reciprocated by a motor 120 fixed to themovableframe plate 72. In the illustrated case, the saddleshaped member122 is welded to the plate 72 and receives the motor 120, and two bandclamps,124,124 surround the motor and the saddle member 122 andhold'the'motor tightly inplace on the saddle member. The nlotor 120 includes adrive shaft 126 having an eccentric crank 128 on the outer. end thereof.Rotatably connected with the crank 128, by means of two ball'bearingunits 130,130, as'shownin FIG. 5, is a conand comprised of two nylonblocks 140. and 142. The block 6 is fixed to awall 144, forming partofthe movable frame, by two bolts 146,146,.asshown best 'inFIGS. 4 and 5.The

heads of the bolts 146,146 are located inenlarged openings passingpartly through the block 140,-and the. bolts have nuts threaded on theirfree ends. The block 1'40partially surrounds the reciprocating part 134.The block 142'is in turn fixed to I the block 140 by two screws 148,148which pass through the block 142 and threadably engage the block140. Theblock At each end of the cutting edge 94 are twoother sharp side 75 142surrounds the remainder of the part 134, and the two blocks 140 and 142together provide a guide opening for the part 134. By removing the twoscrews 148,148, the nylon block 142 is removable from the block 140, andwhen the block 142 is so removed the part 134 may be swung out of itsnormal position to permit replacement of the cutting tool 90, ashereinafter described in more detail.

As shown best in FIG. 5, the reciprocating part 134 is con- I nectedwith a chuck for gripping the cutting tool 90, the chuck including amain body 150 having an upwardly extending stem 152 rotatably supportedby a bushing 154, fixed to the part 134, for rotation about the axis ofreciprocation which is coincident with the central axis of the tool 90.The chuck body 150 is held vertically in place relative to the part 134by a collar 156 fixed to the upper end of the stem 152 by a set screw.Associated with the chuck body 150 is a clamping block 158 which isfixed to the chuck body by two screws 160,160. The upper end of the tool90 is held in the chuck by being clamped between the main body 150 andthe clamping block 158, as shown in FIG. 5. To remove the cutting tool90 from the cutter head, the clamping block 158 is first removed fromthe chuck by removing the screws 160,160, and the nylon guide block 142is then removed by removing the screws 148,148. The reciprocating part134 and the chuck body 150 may thereupon be swung to an out of the wayposition by rotating the crank 132 about the eccentric shaft portion128. The cutting tool 90 may then be lifted from the guide member 104.In replacing the tool in the cutter head, the reverse procedure isfollowed.

From the foregoing description of the reciprocating part 134 and theassociated chuck, it will be understood that the chuck may be rotatedrelative to the part 134, to accordingly rotate the tool about itscentral axis, while the ,tool is reciprocating. Means for so rotatingthechuck relative to the reciprocating part 134 includes a laterallyextending pin 162 fixed to the chuck body 150 and having an outer endreceived in a vertically extending slot 164 formed in a guide block 166preferably made of nylon. The guide block 166 is carried by an annularmember 168 rotatably supported on the guide member 104, by a ballbearing unit 170', for rotation about the central tool axis. Fixed tothe annular member is a gear 172 which meshes with another gear 174fixed to the output shaft 176 of the drive motor 40 supported by abracket 178 forming part of the movable frame. The motor 40 ispreferably a stepping motor, as hereinbefore described in connectionwith FIG. 2, and it will be understood that operation of this motor,through the gears 174 and172, causes rotation of the annular member 168and the guide block 166 fixed thereto. As the guide block 166 rotates,it moves with it the pin 162 which in turn rotates the chuck and thecutting tool.

As mentioned previously in connection with the description of thecontrol system of FIG. 2, the tool rotating motor 40 has associatedtherewith a means for providing a signal representative of the toolangle and, referring to FIGS. 4 and 10, this means comprises a switch 42carried by a supporting plate 180 spaced above the bracket 106 by twosupporting posts 182,182. The switch 42 is located adjacent the annularmember 168 and includes an actuating arm 184 having a roller 186 on itsouter end. The roller 186 rides against the side surface 188 of theannular member 168, and included in this surface, at one point on thecircumference thereof, is a recess 190. The switch 42 has two states ofactuation, one state being reached when the roller 46 is in engagementwith the recess 190, as shown in FIG. 10, and the other state beingreached when the roller engages the surface 188 on either side of therecess 190. Therefore, each time the recess 190 is brought intoregistration with the switch roller 186, the switch 42 produces a signalindicating this particular angular position of the annular member 168and allows the number in the tool angle register of the computer 34 tobe-checked and corrected if necessary. 1

We claim:

1. A cutter head for use in cutting sheet material, said cutter head comrising: a frame, a reciprocating part supported for reciproca ivemovement along an axis 0 reciprocation fixed relative to said frame,means on said frame for reciprocating said reciprocating part along saidreciprocating axis between two points on said axis, a chuck adapted togrip an elongated cutting tool with its central axis generallycoincident with said axis of reciprocation, means connecting said chuckto said reciprocating part permitting rotation of said chuck relative tosaid reciprocating part about said axis of reciprocation and restrainingmovement of said chuck relative to said reciprocating part along saidaxis of reciprocation, a guide member on said frame surrounding saidaxis of reciprocation and adapted to engage a tool received in saidchuck and to support such a tool for reciprocation along and rotationabout said axis of reciprocation, a presser member on said frame havinga surface generally perpendicular to said axis of reciprocation andadapted engage the surface of the material to be cut to limit movementof said cutter head toward said material, and means for adjustablymoving said presser member to different positions along said axis ofreciprocation to vary the amount by which a cutter tool gripped in saidchuck moves beyond said presser member surface during each stroke of itsreciprocation.

2. A cutter head as defined in claim 1 further characterized by saidpresser member being threadably received on said guide member and havingan opening in said face through which a tool gripped in said chuck movesduring its reciprocation.

3. A cutter head as defined in claim 1 further characterized by meansfor rotating said chuck relative to said frame while said chuck isreciprocated by said reciprocating part.

4. A cutter head as definedin claim 3 further characterized by saidmeans for rotating said chuck comprising a part supported on said framefor rotation about said axis of reciprocation and including meansdefining a slot extending generally parallel to said axis ofreciprocation, and a laterally extending arm on said chuck received insaid slot for moving said chuck about said axis of reciprocation inresponse to movement of said slot providing part about said axis ofreciprocation.

